Sulphur-bonded Derivatives

Diglucosyl disulphide octa-acetate has afforded a platinum complex, and the dithlocarbamate derivative (19) has been synthesized from the methyl-2-amino-2-deoxy-a-D-glucopyranoslde acetal by use of carbon disulphide followed by bis-triphenylphosphineplatinum dichloride 

Nakamura, and Y.Morita, Chem. Pharm. Bull., 1985, 5284. 

Fernandez-Bolanos, I.Maya Castilla, and J.Fernandes-Bolanos Guzman, Carbohydr. Res., 1986, 147, 325. 

Yamashita, M.Kobayashi, M.Sugiura, K.Tsunekawa, T.Oshikawa, S.Inokawa, and H.Yamamoto, Bull. Chem. Soc. Jpn., 1986, 175. 

Lajunen, P.Hakkinen, and S.Purokoski, Finn. Chem. Lett., 1986, 13, 21 (Chem. Abstr., 1986, 105, 79 240). 

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The Suzuki coupling of aryl halides was also extended to tosylates recently. Benzothiazole 5-tosylate reacted with m-xylene-2-boronic acid (6.13.) to give the coupled product in 94% yield using palladium acetate and a stericly congested biphenyl based phosphine ligand as catalyst.17 Another class of less commonly utilised cross-coupling partners are methyltio derivatives. In the presence of a copper salt, which activates the carbon-sulphur bond, 2-methyltio-benzotiazol coupled readily with a series of arylboronic acids.18... 

Selenoxothione derivatives can be generated in a similar manner from 1,2,3,4-tetrathia-5-selenepines. Carbon-sulphur bond homolysis is commonly observed in the photochemistry of sulphur-containing... 

Carbon disulphide inserts rapidly into the P—N bond of N-dimethyl-aminophosphines containing phosphorus-sulphur bonds to give thiocarba-moyl derivatives such as Me2NC(S)SPR R2, but similar reactions with... 

An Sj l mechanism has been implicated in the photochemical reaction of diarylsulphides (and the corresponding sulphoxides and sulphones) with the enolate of pinacolone, and with diphenylphosphide anion and diethylphosphite anion.The products are derived from reaction of the anions with aryl radicals formed by cleavage of an aryl sulphur bond in a diarylsulphide radical anion intermediate. Thus (146) is formed from diphenylsulphide and the enolate of pinacolone. 

Ethylene and thioformaldehyde are the products of irradiation of matrix-isolated thietane at lOK. Sulphur-carbon bond homolysis has also been observed on irradiation of the nucleoside membrane transport inhibitor, 6-[ (4-nitrobenzyl) thio] -9- (/8-D-ribofuranosyl) -purine (94), and the oxazolidin-2-one (95) has been converted into the allyl derivative (96) by photochemically induced radical allylation.Efficient conversion of cyclic thioacetals into the corresponding carbonyl compounds under neutral conditions has been achieved by 2,4,6-triphenylpyrylium tetrafluoroborate-sensitised irradiation in moist dichloromethane,and diaryl sulphides and the corresponding sulphoxides and sulphones have been reported to undergo anion-promoted carbon-sulphur bond photocleavageboth processes appear to involve an initial electron transfer. Sulphur-hydrogen bond horaolysis has been reported in t-butanethiol and is also responsible for the photoinitiated thiylation of fluorobromoethylenes and of trialkylethynylsilanes and t-butylacetylene. 

The disulphide (175), obtained by photo-oxidation of 6-mercapto-l,3-dimethyl-lumazine, undergoes photorearrangement to the dithiin derivatives (176) and (177) by way of initial sulphur-sulphur bond homolysis. The photodecomposition of 2,2 -dithiodibenzoic acid derivatives has also been examined. Irradiation of... 

If possible, geminal as well as non>geminal disubstituted derivatives are formed. Reactions of (9) (X = Cl, Ph) with secondary amines follow a non-geminal pathway, with preferential attack from the oxygen side of the ring plane - for (9) (X = Cl) the third chlorine atom to be substituted (with inversion) is the sulphur-bonded one. Reactions of (8) with dimethylamine are less straightforward, involving both solvent-dependence and isomerization reactions. ... 

General discussion of intra- and intermolecular interactions 3 van der Waals interactions 3 Coulombic interactions 5 Medium effects on conformational equilibria 5 Quantum mechanical interpretations of intramolecular interactions 7 Methods of study 8 Introduction 8 Nmr and esr spectroscopy 8 Microwave spectroscopy (MW) 12 Gas-phase electron diffraction (ED) 12 X-ray crystallographic methods 13 Circular-dichroism spectroscopy and optical rotation 14 Infrared and Raman spectroscopy 18 Supersonic molecular jet technique 20 Ultrasonic relaxation 22 Dipole moments and Kerr constants 22 Molecular mechanic calculations 23 Quantum mechanical calculations 25 Conformations with respect to rotation about sp —sp bonds 27 Carbon-carbon and carbon-silicon bonds 28 Carbon-nitrogen and carbon-phosphorus bonds 42 Carbon-oxygen and carbon-sulphur bonds 48 Conformations with respect to rotation about sp —sp bonds Alkenes and carbonyl derivatives 53 Aromatic and heteroaromatic compounds 60 Amides, thioamides and analogues 75 Conclusions 83 References 84... 

The partial desulphurization occurred successfully in the presence of many common functional groups, and was accelerated in polar solvents the rate-controlling step was probably the nucleophilic cleavage of the sulphur-sulphur bond. In accord with these mechanistic conclusions, desulphurization of (132) did not give the thietan derivative (133) but gave (134),... 

Harder nucleophiles often react with thiirans to give a predominance of attack at carbon, with consequent cleavage of the weak carbon-sulphur bond. This strategy has been used to prepare 7-oxa-4-thia-alk-l-enes from alkoxides, thiiran, and allyl chlorides, yS-mercaptoethyl sulphides from thiiran and thiolate ions, thiazines by the CujO-catalysed cyclization of the adducts of a-lithio-isocyanides with thiirans, tautomeric mixtures of (18) and (19) or (20) from thiiran and hydrazones, 7V-methylpyrrolidines from bis(epithio)linoleic acid and methylamine, and 2,4-dimethylhex-5-ene-2-thiol by addition of the Grignard reagent derived from 3-chlorobut-l-ene with 2,2-dimethylthiiran. Methylthiiran has been found to open... 

Tetramesityliridium reacts with nitric oxide by coupling two nitric oxide molecules foiming the hyponitrite complex [Ir(mesityl)4(p-ONNO-x2o) 93 Sulphur dioxide induces insertion of a caibonyl group into an intermediate iridium - nitrogen bond derived from a benzothiazole 2-thiolate ligand Scheme 6,). The product has been structurally characterised. ... 

Surprisingly enough, the effect of ring strain on the electronic structure of the —SO and —S02 groups is rather small. Sulphur charges and S—O BOPs are almost constant in the ring compounds and in the dimethyl derivatives. The only exception is a substantially weaker C—S bond (lower BOP) in ethylene episulphoxide. 

Supplement A The chemistry of double-bonded functional groups (2 parts) Supplement B The chemistry of acid derivatives (2 parts) Supplement C The chemistry of triple-bonded functional groups (2 parts) Supplement D The chemistry of halides, pseudo-halides and azides (2 parts) Supplement E The chemistry of ethers, crown ethers, hydroxyl groups and their sulphur analogues (2 parts)... 

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